Chris Cook got caught peeking and was engulfed at the edge in run support.

Ray Edwards wasn't around to scream obscenities at the Minnesota Vikings' young cornerbacks as he did last November in the final throws of an embarrassing home loss.

But Saturday's exhibition opener at Tennessee provided more than a few reminders the Vikings did virtually nothing to address one of their greatest flaws from a year ago.

Even if Cedric Griffin returns to form after two knee reconstructions, the Vikings need a third cornerback. Every team in the NFL does, with offenses spreading out and subpackage defenses getting deployed on roughly 50% of all snaps.

Allen isn't that guy. He's a dime player at best. It shouldn't surprise anyone when he lets immortals such as Ahmard Hall and Lavelle Hawkins make him look silly in the first three plays from scrimmage.

Cook is supposed to be something more. He's a former second-round draft pick with the size, coverage ability and ball skills to be a starting-caliber cornerback, provided he stays healthy -- which he never was last season.

Yet there was Cook in Saturday's 14-3 loss, looking a little too much like the rookie who was benched twice and memorably exchanged words with Edwards on the bench as the Green Bay Packers roasted the Vikings' secondary in a 31-3 rout on Nov. 21.

Cook missed a tackle on the Titans' fourth play. He repeatedly got wiped out of running plays at the edge by receivers -- something that just can't happen to a Tampa-2 corner. And he dropped coverage when rookie quarterback Jake Locker briefly dropped a snap in the second quarter, letting Yamon Figurs blow by him for a 45-yard touchdown.

"I definitely saw the ball on the ground and just came up thinking that we were going to get the ball," Cook said. "Just pursuing the ball, and they got a lucky play on me."

Defensive coordinator Fred Pagac clutched Cook's helmet when he returned to the sideline. Secondary coach Joe Woods had words for Cook, too.

"Keep playing," coach Leslie Frazier said. "No matter what happens, just keep playing. That's what their receiver did, and they end up with a big play."

Cook wasn't far from the Titans' second touchdown either, but a receiver easily kept him at bay as Jamie Harper turned the corner on a stretch play.

Despite having a safety's build at 6-foot-2 and 212 pounds, Cook has never been a particularly physical player in run support. He's supposed to make his mark by using his long arms to play press coverage, beat up receivers at the line and sink into Cover-2.

The Vikings' decision to bypass help through free agency or the first four rounds of the NFL Draft suggests they believe it's only a matter of time before Cook becomes that player. But Frazier admitted before camp the secondary was the greatest unknown on his roster, and Saturday's travails did nothing to sort things out.

"We're going to play them as much as we can in this preseason," Frazier said, "because when we line up against San Diego, we'd like to feel good about what guys are going to be our guys -- whether we're going three corners and playing nickel or if we're going four corners and playing dime. We've got to keep letting those guys play and make that determination."

With Griffin and Antoine Winfield getting the night off, Marcus Sherels was the third corner in the nickel, set up the Titans' second touchdown with a pass-interference penalty and let Damian Williams streak past him for a 28-yard gain.

Brandon Burton, the fifth-round pick from Utah, is a contributing backup type who had his share of rough moments in camp. Cord Parks delivered one big hit on Saturday, but there are reasons he's been bouncing around practice squads for two years.

No, if the Vikings want to solidify their cornerback situation, there are only two options: get Cook to play to his potential or patch a hole as they did last year with journeyman Frank Walker, who signed with the Titans and stripped a deep ball out of Devin Aromashodu's hands.

It looked a lot like one of the plays Cook made the first week of camp last year, before meniscus surgery on both knees sapped his legs and raised questions about his future that remain unanswered.

"Rough year last year," Cook said. "I'm kind of past that. Well, not even kind of past that -- I am past that. I just want to contribute in any way possible, whether it be starting eventually, the nickel package, special teams. Whatever it takes."